The need for improvements in lead-acid storage batteries is widely recognized. One example of a use in which a better battery is needed is in Hybrid Electric Vehicles (HEVs), such as micro-hybrid vehicles (μHEVs). Micro-hybrid vehicles are different from conventional vehicles, as they are designed to shut the engine off when the vehicle comes to a stop. The engine is then restarted immediately before the vehicle begins moving again. As a result, the lead-acid battery is forced to discharge during the period the engine is off to provide support for electrical loads in the vehicle and discharge at a high rate to start the vehicle. This will happen many times during a normal trip as opposed to only once for a conventional vehicle. The lead-acid battery therefore will discharge many times and be required to charge quickly in order to replenish the charge depleted during the stop event to allow the vehicle to complete another stop-start event. This new requirement for lead-acid battery is difficult to achieve.
Accordingly, a continual need exists for improved lead-acid batteries.